Aspects of the disclosure are related, in general, to the field of manufacturing sulfuric acid and, more specifically, to the field of on-site manufacture of relatively small amounts of sulfuric acid for on-site use of mining, fertilizer production, ethanol production, wastewater treatment and other uses.
Sulfuric acid may be produced in very large quantities (several thousand tons per day) at a manufacturing facility. Raw sulfur may be burned with air to form sulfur dioxide. The sulfur dioxide gas may then be passed through a catalyst at high temperature (sometimes vanadium oxides at 500-700 C) to convert (oxidize) the sulfur dioxide to sulfur trioxide gas. The sulfur trioxide gas may then be scrubbed (mixed) with concentrated (93-98%) sulfuric acid. Under these conditions, the sulfur trioxide may then react with water to form sulfuric acid. Make-up water may be added to maintain the concentration and continuously produce sulfuric acid. At a manufacturing facility, this may be accomplished by burning 1000's of tons of sulfur per day. The acid may then be shipped via semitrailer, train or other means to the customer. The shipping of sulfuric acid may be very costly, and dangerous.